Effect of hydrothermal treatment on linear and nonlinear rheological properties of highland barley gels

Highland barley gels were subjected to hydrothermal treatment, and the rheological properties of both small and large strain amplitude oscillation shear (SAOS/LAOS) were investigated in this study. The results showed that untreated highland barley gels formed a wider linear viscoelastic region (LVE) than hydrothermal-treated gels, and the storage moduli (G′) & loss moduli (G″) decrease as the hydrothermal treatment time increased. In particular, the LAOS behavior of highland barley gels in strain sweep was changed from Type Ⅳ strong strain overshoot to Type Ⅰ strain thinning by hydrothermal treatment. The frequency dependence of the viscoelastic moduli (G'∝ω^0.41−0.74 and G''∝·ω^0.41−0.77) for hydrothermal gels was classified as an entangled network. The creep behavior fitted well with a four-element Burgers model (R²>0.93). Moreover, after 10 min treatment, hydrothermal treatment had changed the gels from elastic-dominated to viscous-dominated, and the strain-stiffening/shear-thinning properties of highland barley gels also increased.